By way of background, it is instructive to briefly consider the history of verify and record systems used in connection with radiation therapy treatment of patients using linear accelerators or other megavoltage radiation units. Verify and record systems were originally designed to verify that radiation treatments were set up correctly by the radiation therapy technologist (RTT). This was accomplished through verification that certain key parameters were within predetermined tolerances. The verify and record process has evolved more recently into an automated set-up procedure that emphasizes rapid through-put, while de-emphasizing verification of treatment parameters that previously were set manually by the RTT. Some record and verify systems currently in use actually take control of the manual process by changing physician-selected field sizes, even though the field sizes fall within selected tolerance limits. The trend toward automated systems has led to reduced interaction between the user and the accelerator which has both positive and negative implications. The philosophy of delivering radiation treatment based on an automated set-up model is grounded in the desire to reduce the potential for human error in the set-up process. The downside of the automated or “black box” approach is the disengagement of the RTT from parameter adjustment, i.e., in relieving the RTT of the task of setting the patient treatment parameters through adjustment of the linear accelerator. The negative aspect of this is that if the RTT does not have to set the parameters manually, the RTT is less conditioned to perform the function manually and, therefore, less conditioned to detect errors when these errors occur, whether these errors are dosimetry programming or process errors and whether these errors occur in manual or automated set-up modes. When the RTT is detached from the procedure of manually setting up the patient for treatment, it becomes more difficult for the overall treatment process to recover should the automated process fail. In this regard, when an RTT sets up a patient manually, the RTT “rehearses” the recovery procedure that would be used if the automated primary process should fail. However, when automated set-ups are employed, the RTT is less “rehearsed” in recovering efficiently when the automated process is not available, because such rehearsal of recovery procedures is not integral to automated treatment delivery. The more safety critical the task, the more the recovery should be rehearsed.
Given current trends in the medical industry, the trend toward automated set-up is irreversible. Further, because of a number of factors including cost pressures, the trend toward staffing reduction is irreversible, at least in the near term. It also appears clear that the electronic record will not totally replace the paper chart, at least not in the near term. In this regard, even if it were proven better for patient care to chart electronically, physician resistance will hinder widespread adoption in the foreseeable future. In general, physicians will not abandon paper charts, either from habit or for medical-legal reasons. Accordingly, the need for maintaining a paper record during implementation of electronic medical record keeping will continue. As a consequence, a further vulnerability of automated radiation treatment systems (in addition to the disengagement of the RTT from the manual recovery process when the automated system is temporarily down), is the potential for mismatches between the electronic record and the paper medical record. These mismatches are commonly due to a failure of the RTT to document treatments in the paper record when the automated system logs the event. The problem of electronic record and paper mismatches is increasing in the specialty of radiation oncology, as reported by clinical medical physicists.
It should be understood that disengagement of the RTT from the manual recovery process increases risk for patient care because the verify and record systems, in many recent configurations, do not check for human error. Record and verify systems, when programmed and executed correctly, can prevent some errors, but not all. Record and verify systems in current use cannot detect human errors when the system itself is the primary process. Additionally, as indicated above, the disengagement of the RTT from linear accelerator parameter adjustment also can disengage the RTT from subtle cues regarding patient identification and radiation field placement. It would be desirable if record and verify systems were configurable to allow automated set-ups at selected times for certain radiation therapy technologists and not for others, such as, for example, when the manual skills of selected RTTs are being assessed. However, the overall trend is clearly toward automated set-up because of the improved throughput which results, as well as the industry-wide momentum toward multi-leaf collimator therapy, which is more optimally performed with automation.
Greater automated throughput can lead to greater risk for other reasons as well. Increased automation means greater potential for a mistake occurring through dose calculation error, with the danger of the error being repeated without prompt detection once the error does occur. The emphasis on throughput also increases the probability of errors in the actual treatment process, characterized by patient identification errors, field sequence errors and field alignment errors. Major preventable ways to harm patients through treatment process failures include (1) treating the wrong patient, i.e., treating a patient with a radiation treatment intended for another patient; (2) treating the right patient, but on a day when the patient is not supposed to receive treatment until other evaluations are performed first (e.g., treating a patient when the patient should have been seen by the doctor prior to the treatment delivery), and (3) treating the right patient but with the improper treatment set-up, i.e., treating with a wedged field without a wedge, treating with the wrong monitor units (MU) programmed into the accelerator, or treating with the wrong energy. In addition, as described above, in the event that the record and verify device should be temporarily unavailable due to a network, or other, problem, there is a distinct possibility or even an increased probability of parameter selection errors due to human error, because the process of automation can change the behavior of the user, making the user more dependent on automation. It is noted that more combination chemotherapy with radiation increases toxicity and therefore increases the potential harm that may occur to a patient if the patient receives the wrong treatment or if the patient is treated without proper evaluation before treatment. Moreover, pushing patients to the limit of tissue tolerance increases the potential for adverse events. Automated treatment may increase the possibility of undetected mistakes related to automated set-up, thereby increasing the possibility of patient injury.
As indicated above, the transition to automated treatment system tends to distract the RTTs for a number of reasons. First, and very basically, the new technology creates a new process. Further, the new process diverts RTTs from traditional cross checks in the treatment room. This is true of systems now in use such as the VARIS, IMPAC and LANTIS systems. In addition, visual distractions are created and the RTTs are diverted from paper chart documentation which can be critical in the safe treatment of a patient.
Although the focus above has been on radiation therapy, it will be appreciated that similar problems exist in other medical treatment settings including chemotherapy as well as in neonatal care, dispensing of medications on both an inpatient and outpatient basis and in other inpatient and outpatient applications wherein patient verification, medication verification, medication delivery device verification and the like are of importance.